MX2013014885A

MX2013014885A - Polyol formulations for improved green strength of polyisocyanurate rigid foams.

Info

Publication number: MX2013014885A
Application number: MX2013014885A
Authority: MX
Inventors: Jorge Jimenez; Michael J Skowronski; Kelly R Flaherty; Woo-Sung Bae; Giuseppe Lista
Original assignee: Dow Global Technologies Llc
Priority date: 2011-06-29
Filing date: 2012-05-21
Publication date: 2014-01-31
Also published as: EP2726533A1; US20140186611A1; WO2013002914A1; CN103619904A; JP2014520909A

Abstract

Polyesters and polyol formulations comprising polyesters used in the preparation of polyisocyanurate rigid foams with improved green strength properties are provided. In some embodiments, a polyester which is the reaction product of (a) an aromatic component comprising 80 mole percent or greater of terephthalic acid, (b) at least one polyether polyol having a nominal functionality of 2, a molecular weight of 150 to 1,000 and a polyoxyethylene content of at least 70% by weight of the polyether polyol, (c) at least one glycol different than (b) having a nominal functionality of 2 and a molecular weight from 60 to 250, and (d) at least one polyol having a molecular weight of 60 to 250 and a nominal functionality of at least 3, wherein (a), (b), (c), and (d) are present in the reaction on a percent weight basis of 20 to 60 weight percent of (a), 20 to 50 weight percent of (b), 10 to 30 weight percent of (c), and 5 to 20 weight percent of (d) is provided.

Description

POLYOL FORMULATIONS FOR RESISTANCE OF RIGID FOAMS OF POLI ISOC IA U RATO Field of the Invention The embodiments of the present invention relate to a polyol formulation comprising certain polyols used in the preparation of rigid polyisocyanurate foams. Said foams are particularly useful in the production of composite elements.

Background of the Invention Polyisocyanurate foams have the ability to be tailored for particular applications through the selection of raw materials that are used to form the polymer. The rigid types of polyisocyanurate foams are used as insulation foams for household appliances and other applications of thermal insulation.

Rigid polyisocyanurate foams can be produced using either a continuous process or a batch process. In a continuous process, also called a double-band lamination process (DBL), normally two "trimmings", in the form of continuous garrison sheets, are placed parallel to each other, with one over the other. The garrisons are driven to a conveyor belt, which has the purpose of both heating the fittings as maintenance of fittings in position. Just before entering the conveyor belt, a quantity of the formulation for the foam layer is transferred over the lower lining, so that the rising foam is sandwiched between the lower and upper linings. The foam is additionally fitted on the sides, that is to say, lateral containment. The polymerization process, which includes foaming, is completed as the material moves along the conveyor belt. After leaving the conveyor belt, the pellets are cut to the desired lengths. In some continuous processes, a single lining face is used with the conveyor belt functioning as the second lining sheet with the foam layer formed between the single lining sheet and the conveyor belt.

Resistance is a measure of the initial fiber properties of the demolding material. In the DBL process, the line speed of the conveyor belt is limited by the reactivity profile and the strength of the panel at the end of the manufacturing line. If the line speed is too high for a formulation, the resistance at the end of the line will be reduced, which may result in unacceptable subsequent expansion of the panel at the end of the production line and other undesirable effects including shrinkage , deformation, and damage due to stacking and handling. Attempts to increase the resistance and the corresponding line speed have included the increase of the catalyst level of the formulation. However, the level of catalyst has been found to reduce cream time and gel time, which can have detrimental effects during foam formation.

Brief Description of the Invention The embodiments of the present invention relate to certain polyols, a polyol formulation comprising said polyols used in the preparation of rigid polyisocyanurate foams with improved strength properties and the foams produced from said formulations. In one embodiment, a polyester is provided. The polyester is the reaction product of at least: (a) an aromatic component comprising 80 mole percent or more of terephthalic acid; (b) at least one polyether polyol having a nominal functionality of 2, a molecular weight of 150 to 1,000 and a polyoxyethylene content of at least 70% by weight of the polyether polyol; (c) at least one deferent glycol of (b) having a nominal functionality of 2 and a molecular weight of 60 to 250; Y (d) at least one polyol having a molecular weight of 60 to 250 and a nominal functionality of at least 3; where, a, b, c, and d are present in the reaction in a percentage basis by weight of 20 to 60 percent by weight of (a), 20 to 50 percent by weight of (b), 10 to 30 percent by weight of (c), and 5 to 20 percent by weight of (d).

In another embodiment, a polyol formulation is provided wherein the polyol formulation comprises: a first polyol, which is the polyester polyol as described above; at least one second polyether polyol having a functionality of 2 to 8, and a molecular weight of 100 to 2,000; and wherein the first to second polyols are present in a percent by weight of the polyol blend from 20 to 90 percent by weight of the first polyol and from 10 to 80 percent by weight of the second polyol.

In another embodiment, a reaction system is provided for the production of a rigid polyisocyanurate foam. The reaction system comprises: (A) a polyol formulation comprising: (1) a polyester such as that described above; (B) a polyisocyanate component, (C) blowing agents; (D) catalyst; Y (E) optionally, additives and auxiliaries.

In another embodiment, a reaction system is provided for the production of a rigid polyisocyanurate foam. The reaction system comprises: A) a polyol formulation comprising a first polyol, which is the polyester polyol as described above; at least one second polyether polyol having a functionality of 2 to 8, and a molecular weight of 100 to 2,000; and wherein the first and second polyols are present in a percentage by weight of the polyol mixture from 20 to 90 percent by weight of the first polyol and from 10 to 80 percent by weight of the second polyol: (B) a polyisocyanate component, (C) blowing agents; (D) catalyst; Y (E) optionally, additives and auxiliaries.

In yet another embodiment, a process for preparing a rigid polyisocyanurate foam is provided. The procedure includes: to. form a reaction system that contains at least: 1. a polyol formulation as described above; 2. a polyisocyanate component; Y 3. at least one hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether or physical blowing agent of dialkyl ether substituted by fluorine; 4. catalyst; 5. optionally, additives and auxiliaries, and b. subjecting the reaction system to conditions such that the reaction system expands and cures to form a rigid polyisocyanurate foam.

In yet another embodiment, a composite element is provided. The composite element comprises: i) a lining layer; ii) a rigid foam comprising the reaction product of: (A) a polyol formulation as described above; Y (B) a polyisocyanate component; (C) blowing agents; (D) catalyst; (E) optionally, additives and auxiliaries, and iii) optionally, a second lining layer.

In another embodiment, a process for preparing a composite element is provided wherein the rigid foam (ii) adheres to (i) and (ii) and is prepared between (i) and (iii) by reacting the isocyanate formulation and polyol at a temperature from 25 ° C to 70 ° C.

In the additional embodiments, said additives or optional auxiliaries are selected from the groups consisting of dyes, pigments, internal mold release agents, fire retardants, fillers, reinforcers, plasticizing agents, smoke suppressants, fragrances, anti-static agents, biocides, antioxidants, light stabilizers, adhesion promoters, surfactants and combinations of these.

Detailed description of the invention The embodiments of the present invention relate to polyester polyols, polyol formulations comprising said polyester polyols, and the use of said polyol formulations in the preparation of rigid polyisocyanurate foams having an improved strength. Said foams are particularly useful in the production of composite elements.

The use of a polyol formulation in the preparation of polyisocyanurates by reaction of the polyol formulation with a polyisocyanate in the presence of a catalyst, and possibly other ingredients, is well known. Aromatic polyester polyols, such as those based on the dimethyl terephthalate (DMT) process residue, are widely used in the manufacture of rigid polyisocyanurate panels to assist the combustibility performance of the foams. Typical formulations using these aromatic polyester polyols show a tendency towards poor strength and decreased production line speed. Attempts to modify polyisocyanurate formulations based on DMT to improve the resistance have resulted in other negative consequences in terms of the processing and / or properties of the foam.

The polyol formulations containing the polyester polyols based on terephthalic acid described herein have resulted in a polyisocyanurate foam having a similar reactive profile, but a superior strength during the typical time frame in which, a panel of Double fitting could be a processing through a double-band lamination system (for example, less than 8 minutes). This superior resistance in similar reactivity results in a panel having an increased "hardness" at the end of the production line with a reduced potential for subsequent expansion, shrinkage and deformation and stacking and handling damage.

The polyester of the present invention is the reaction product of at least a) an aromatic component; b) at least one polyether polyol having a nominal functionality of 2 and a polyoxyethylene content of at least 70% by weight of the polyether polyol; c) at least one glycol other than (b) having a nominal functionality of 2 and a molecular weight of from 60 to 250 and d) at least one polyol having a molecular weight of from 60 to 250 and a nominal functionality of at least less 3. It has been found that such polyesters can be used to produce foams of Polyisocyanurate that have improved resistance.

The aromatic component (a) of the polyester present is derived mainly from terephthalic acid. The terephthalic acid will generally comprise 80 mole percent or more of the aromatic component (a). In the further embodiments, the terephthalic acid will comprise 85 mole percent or more of the aromatic component (a). In other additional embodiments, the terephthalic acid will comprise 90 mole percent or more of the aromatic component (a) to make the polyester. In another embodiment, the aromatic component (a) comprises more than 95 mole percent terephthalic acid. In another embodiment, the aromatic component (a) is essentially derived from terephthalic acid. While the polyester can be prepared from substantially pure terephthalic acid, more complex ingredients can be used, such as waste waste or discarded sidestream from the manufacture of terephthalic acid. Other types of aromatic materials, which may be present, include, for example, italic anhydride, trimellitic anhydride, dimethyl terephthalic residues.

The aromatic component (a) can comprise at least 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, or 55% by weight of the total reaction or reaction mixture. The aromatic component (a) can comprise up to 25% by weight, 30% by weight, 35% by weight, 40% by weight, weight, 45% by weight, 50% by weight, 55% by weight, or 60% by weight of the total reaction. In certain embodiments, the aromatic component (a) may comprise from 20% by weight to 60% by weight of the total reaction. In a further embodiment, the aromatic component (a) comprises 30% by weight or more of the reaction. In still a further embodiment, the aromatic component (a) comprises 35% by weight or more of the reaction.

The polyether polyol component (b) can be obtained by alkoxylation of suitable starting molecules (initiators) with a C2 to C4 alkylene oxide, such as ethyl oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, tetramethylene oxide or a combination of two or more thereof. The polyether polyol component (b) will generally contain more than 70% by weight of oxyalkylene units derived from ethylene oxide (EO) units and preferably at least 75% by weight of oxalkylene units derived from EO. In other embodiments, the polyether polyol component (b) will contain more than 80% by weight of oxyalkylene units derived from EO and in a further embodiment, 85% by weight or more of the oxyalkylene units will be derived from EO. In some embodiments, the ethylene oxide will be the alkylene oxide only used in the production of the polyol. When an alkylene oxide other than EO is used, it is preferred that the additional alkylene oxide, such as propylene or butylene oxide is fed as a coalition with the EO or is fed as an internal block. The catalyst for this polymerization can be, either anionic or cationic, with catalysts such as potassium hydroxide, cesium hydroxide, boron trifluoride or a double cyanide complex (DMC) catalyst such as zinc hexacyanocobaltate or quaternary phosphazene compound. . In the case of alkaline catalysts, these alkaline catalysts are preferably removed from the polyol at the end of production by the appropriate finishing step, such as coalescence, separation of magnesium silicate or acid neutralization.

The polyether polyol component (b) generally has a molecular weight from 150 to 1,000. In one embodiment, the average molecular weight number is 160 or greater. In a further embodiment, the average molecular weight number is less than 800, or even less than 600. In a further embodiment, the average molecular weight number is less than 500.

The initiators for the production of the polyether polyol component (b) have a functionality of 2. As used in the present description, unless stated otherwise, the functionality refers to the nominal functionality. Non-limiting examples of such initiators include, for example, ethylene glycol, diethylene glycol, propylene glycol, water and combinations thereof.

The polyether polyol component (b) can comprise at least 20% by weight, 30% by weight, 35% by weight, 40% by weight, or 45% by weight of the total reaction. The polyether polyol component (b) can comprise up to 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight or 50% by weight of the reaction total. In certain embodiments, the polyether polyol component (b) can comprise from 20% by weight to 50% by weight of the total reaction. The polyether polyol component (b) generally comprises from 20 to 50 percent by weight of the total reaction. In a further embodiment, the polyether polyol component (b) will comprise from 30 to 50% by weight of the total reaction. In another embodiment, the polyether polyol component (b) will comprise at least 35% by weight of the total reaction.

In addition to the aromatic component (a) and the polyether component of polyether (b), the reaction for producing the polyester additionally contains one or more glycols having a molecular weight of 60 to 250 (component c), which is different from (b) Said glycol, or mixture of glycols, will generally have a nominal functionality of 2.

In one modality, 2 functional glycols of the component (c) can be represented by the formula: OH- (CH2-CH-0) "- H 1 R (Formula I) wherein R is hydrogen or a lower alkyl of 1 to 4 carbon atoms and n is selected to provide a molecular weight of 250 or less. In a further embodiment, n is selected to provide a molecular weight of less than 200. In a further embodiment, R is hydrogen. Non-limiting examples of glycols, which may be used in the present invention include, ethylene glycol, diethylene glycol and other polyethylene glycols, propylene glycol, dipropylene glycol, etc.

Component (c) may comprise at least 10% by weight, 12% by weight, 15% by weight, 18% by weight, 20% by weight, or 25% by weight of the reaction total. Component (c) can comprise up to 12% by weight, 15% by weight, 18% by weight, 20% by weight, 25% by weight, or 30% by weight of the total reaction. Component (c) will generally comprise at least 10 percent by weight of the reaction and generally less than 30 percent by weight of the reaction to make the polyester.

The reaction for producing the polyester can additionally contain a polyol having a nominal functionality of 3 or more and a molecular weight of 60 to 250 (component d). Three functional polyols include, for example, glycerin and trimethylolpropane. Polyols of higher functionality include, for example, pentaerythritol.

Component (d) may comprise at least 5% by weight, 7% by weight, 10% by weight, 15% by weight, 18% by weight of the total reaction. Component (d) may comprise up to 7% by weight, 10% by weight, 15% by weight, 18% by weight, or 20% by weight of the total reaction. Component (c) can generally comprise at least 5 percent by weight of the reaction and generally less than 20 percent by weight of the reaction to make the polyester. In another embodiment, the glycol component (b) will comprise more than 7% by weight of the total reaction. In a further embodiment, the glycol component (d) will be less than 18% by weight of the total reaction.

Based on the components for the manufacture of polyester, polyester will have a nominal functionality greater than 2.3 and generally no greater than 2.7. In a further embodiment, the polyester has a functionality of 2.5 or less, for example, a functionality of 2.4. The amount of materials used to make the polyester will generally provide a polyester having a hydroxyl number from 200 to 400. In the additional embodiments, the hydroxyl number of the polyester is less than 350.

By including a specified amount of the polyethylene oxide based on the polyether polyol together with other components as specified above, together with the aromatic component, the viscosity of the polyester Resulting, it is generally less than 15,000 cps (mPa * s) at a temperature of 25 ° C, measured by UNI EN ISO 3219. In a further embodiment, the viscosity of the polyester is less than 10,000 cps (mPa * s). Although it is desirable to have a polyester with a viscosity as low as possible, due to practical chemical limitations and end-use applications, the viscosity of the polyester will generally be greater than 1,000 cps (mPa * s).

A polyester of the present invention can include any minor amounts of unreacted glycol remaining after the preparation of the polyester. Although not desirable, the polyester can include up to about 30 percent by weight free of glycol / polyols. The glycol-free content of the polyester of the present invention is generally from about 0 to about 30 percent by weight, and usually from 1 to about 25 percent by weight, based on the total weight of the polyester. The polyester may also include small amounts of non-esterified aromatic component. Normally, the non-esterified aromatic materials will be present in an amount of less than 2 percent by weight based on the total weight of the components combined to form the polyester of the present invention.

The polyester can be formed by the polycondensation / transesterification and polymerization of components (a), (b), (c) and (d) under conditions well known in the art. See, for example, the publication by G. Oertel, "Polyurethane Handbook" (Polyurethane Handbook), Cari Hanser Verlag, Munich, Germany 1985, pages 54 to 62 and the publication by Mihail Lonescu, "Chemistry and technology of polyols for polyurethanes" (Chemistry and Technology of Polyols for Polyurethanes), Rapra Technology, 2005, pages 263 to 294. In general, the synthesis is performed at a temperature from 180 to 280 ° C. In another embodiment, the synthesis is carried out at a temperature of at least 200 ° C. In a further embodiment, the synthesis is carried out at a temperature of 215 ° C or higher. In a further embodiment, the synthesis is carried out at a temperature of 260 ° C or lower.

Although the synthesis can occur under reduced or increased pressure, the reaction is usually performed close to atmospheric pressure conditions.

Although synthesis can occur in the absence of a catalyst, catalysts that promote the -sterification / transesterification / polymerization reaction can be used. Examples of such catalysts include, tetrabutylitanate, dibutyl tin oxide, potassium methoxide, or zinc, lead or antimony oxides; titanium compounds, such as titanium (IV) isopropoxide and titanium acetylacetonate. When used, said catalyst is used in a amount of 0.005 to 1 percent by weight of the reaction. In the additional embodiments, the catalyst is present in an amount from 0.005 to 0.5 percent by weight of the total reaction.

The volatile product (s) of the reaction, for example, water and / or methanol, is generally peeled off in the process and forces the ester exchange reaction to complete.

The synthesis, totally takes from one to five hours. The actual length of time required varies, of course; with catalyst concentration, temperature, etc. In general, it is desired not to have a too long polymerization cycle, both for economic reasons and for the reason that if the polymerization cycle is too long, thermal degradation may occur.

The polyester described in the present description can be part of a polyol formulation for making various polyisocyanurate products. The polyol formulation, also referred to as the isocyanate reactive component, together with an isocyanate component integrates a reaction system to produce a polyisocyanurate foam. Depending on the application, the polyester will generally vary from 20 to 90% by weight of the total polyol formulation. The polyester can comprise at least 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight weight, or 95% by weight of the total polyol formulation. The polyester can comprise up to 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 95% by weight, or 100% by weight of the total polyol formulation. The amount of the polyester, which can be used for particular applications, can be readily determined by those skilled in the art.

Other representative polyols useful in the polyol formulation may include polyether polyols, polyester polyols other than the polyester of the present invention, acetal resins terminated by polyhydroxy, and hydroxyl-terminated amines. Alternative polyols that can be used include polyalkylene carbonate based polyols and polyphosphate based polyols. Polyether or polyester polyols are preferred. The polyether polyols prepared by adding an alkylene oxide, such as ethylene oxide, propylene oxide, butylene oxide or a combination thereof, for an initiator having from 2 to 8 active hydrogen atoms. The functionality of the polyols used in the polyol formulation will depend on the end use application known to those skilled in the art. Sayings poMols advantageously have a functionality of at least 2, preferably 3 and up to 8, preferably up to 6, active hydrogen atoms per molecule. The polyols used for rigid foams, generally have a hydroxyl number of from about 200 to about 1,200 and more preferably from about 250 to about 800.

Polyols that are derived from renewable resources such as vegetable oils or animal fats can also be used as additional polyols. Examples of said polyols include castor oil, hydroxymethyl hydrated polyethers such as those described in WO 04/096882 and WO 04/096883, hydroxymethylated polyols such as those described in US Patent Nos. 4,423,162.; 4,496,487 and 4,543,369 the "blown" vegetable oils, such as those described in the published North American patent applications 2002/0121328, 2002/0119321 and 2002/0090488.

The increase of the crosslinking network of the polyol formulation may contain a higher functional polyol having a functionality of 4 to 8. Initiators of said polyols include, for example, pentaerythritol, sorbitol, sucrose, glucose, fructose or other sugars. , and the like. Said higher functional polyols will have an average hydroxyl number from about 200 to about 850, preferably from about 300 to about 770. Other initiators may be added to the higher functional polyols, such as a glycerin to produce the co-initiated polyols of functionality from 4.1 to 7 hydroxyl groups per molecule and an equivalent hydroxyl weight of 100 to 175 When used, said polyols will generally comprise from 10 to 50% by weight of the polyol formulation to make a rigid foam, depending on the particular application.

The polyol formulation can contain up to 20% by weight of yet another polyol, which is not polyester, a polyol initiated by amine or a higher functional polyol and which has a hydroxyl functionality of 2.0 to 5.0 and an equivalent weight of hydroxyl from 90 to 600.

For construction applications, the polyol formulation may also include a polyol formed by alkoxylation of a phenol-formaldehyde resin product. Said polyols are known in the art as the Novolac polyols. When used in a polyol formulation, Novolac polyols can be present in an amount of up to 20% by weight of the total polyol formulation.

In one embodiment, the present invention provides a polyol formulation comprising from 30 to 80 percent by weight of a polyester as described above and the remainder is at least one polyol or one combination of polyols having a functionality of 2 to 8 and a molecular weight of 100 to 10,000. The at least one polyol can have a functionality of 2 to 8, and a molecular weight of 100 to 2,000.

Specific examples of polyol formulation suitable for the production of a rigid foam for construction applications having improved strength include a blend of from 20 to 90% by weight of the polyester of the present invention; from 10 to 80% by weight of sorbitol or sucrose / glycerin initiated by polyether polyol wherein the polyol or polyol mixture has a functionality of 3 to 8 and an equivalent hydroxyl weight of 200 to 850, and if present up to 20% by weight of another polyol having a hydroxyl functionality of 2.0 to 5.0 and an equivalent hydroxyl weight of from 90 to 500.

Polyol formulations as described in the present description can be prepared by making individual constituent polyols, and then mixing them together. Alternatively, the polyol formulations, not including the polyester, can be prepared by forming a mixture of the respective initiator compounds, and subsequently alkoxylating the initiator mixture to form the polyol formulations directly. The combinations of these methods can also be used.

In another modality, a system of reaction for the production of a rigid foam. The reaction system comprises (A) a polyol formulation as described above, (B) a polyisocyanate component, and (C) optionally, additives and auxiliaries. Said additives or optional auxiliaries are selected from the groups consisting of dyes, pigments, internal mold release agents, surfactants, fire retardants, fillers, reinforcers, plasticizing agents, smoke suppressants, fragrances, anti-static agents , biocides, antioxidants, light stabilizers, adhesion promoters, and combinations of these.

Polyisocyanates suitable for the production of polyurethane products include aromatic, cycloaliphatic and aliphatic isocyanates. Such isocyanates are well known in the art.

Examples of suitable aromatic isocyanates include the 4,4'-, 2, 4"and 2,2'-isomers of diphenylmethane diisocyanate (MDI), mixtures thereof and polymeric and monomeric MDI mixtures, toluene-2,4- and 2,6-diisocyanates (TDI), m- and p-phenylene diisocyanate, chlorophenylene-2,4-diisocyanate, di-f-nylene-4,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 3 -methyldiphenyl-methane-4,4'-diisocyanate and diphenyl ether diisocyanate and 2,4,6-triisocyanatotoluene and 2,4,4'-triisocyanatodiphenylether.

A crude polyisocyanate can also be used in the practice of the present invention, such as the crude toluene diisocyanate obtained by the phosgenation of a mixture of diamine of toluene or the crude diphenylmethane diisocyanate obtained by the phosgenation of the crude methylene diphenylamine. In one embodiment, TDI / MDI mixtures are used.

Examples of aliphatic polyisocyanates include ethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,3-y / o, 4-bis (isocyanatomethyl) cyclohexane (including cis- or trans-isomers of any), isophorone diisocyanate (IPDI), tetramethylene-1,4-diisocyanate, methylene bis (cyclohexanoisocyanate) (H12MDI), cyclohexane 1,4-diisocyanate, 4,4'-dicidhexylmethane diisocyanate, saturated analogs of the aromatic isocyanates mentioned above and mixtures thereof.

Derivatives of any of the above polyisocyanate groups containing biuret, urea, carbodiimide, allophonate and / or isocyanurate groups can also be used. These derivatives often have increased isocyanate functionalities and are desirably used when a more highly cross-linked product is desired.

For the production of rigid polyurethane or polyisocyanurate materials, the polyisocyanate is generally a diphenylmethane-4,4'-diisocyanate, di-n-methylmethane-2,4'-diisocyanate, polymers or derivatives thereof or a mixture thereof. In a preferred embodiment, the prepolymers Isocyanate-terminated products are prepared with 4,4'-MDI, or other mixtures of MDI containing a substantial portion or the 4,4'-isomer or modified MDI as described above. Preferably, the MDI contains from 45 to 95 percent by weight of the 4,4'-isomer.

The polyisocyanate is used in an amount sufficient to provide an isocyanate index of 150 to 800. The isocyanate index is calculated as the number of reactive isocyanate groups provided by the polyisocyanate component divided by the number of isocyanate-reactive groups in the composition which forms polyurethane (which includes those contained by isocyanate-reactive blowing agents, such as water) and multiplied by 100. It is considered that water has two isocyanate-reactive groups per molecule for the purposes of calculating the isocyanate index . For rigid urate polyisocyan foam applications, the preferred isocyanate index is generally from 180 to 600 and in an additional embodiment, from 200 to 400. In another embodiment, the index is 205 or greater.

It is also possible to use one or more chain extenders in the reaction system for the production of polyurethane or polyisocyanurate products. The presence of an agent extending the chain is provided for desirable physical properties of the resulting polymer. The extenders of The chain may be mixed with the polyol formulation or may be present as a separate stream during the formation of the polyurethane or polyisocyanurate polymer. A chain extender is a material having two isocyanate reactive groups per molecule and an equivalent weight per isocyanate reactive group of less than 400, preferably less than 300 and especially 31 to 125 daltons. The crosslinkers may also be included in formulations for the production of polyurethane or polyisocyanurate polymers of the present invention. "Crosslinkers" are materials having three or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate reactive group of less than 400. The crosslinkers contain from 3 to 8, especially from 3 to 4 hydroxyls, primary amine groups or secondary amine groups per molecule and have an equivalent weight from 30 to about 200, especially from 50 to 125.

The polyols of the present invention can be used with a wide variety of blowing agents. The blowing agent used in the polyisocyanurate forming composition includes at least one physical blowing agent, which is a hydrocarbon, hydrofluorocarbon, hydrochlorofluorocarbon, fluorocarbon, dialkyl ether, or a dialkyl ether substituted by fluorine or a mixture of two or more of them. Blowing agents of these types include propane, isopentane, n-pentane, n-butane, isobutane, isobutene, cyclopentane, dimethyl ether, 1,1-dichloro-1-fluoroethane (HCFC-141b), chlorodifluoromethane (HCFC-22), 1-chloro-1,1-difluoroethane (HCFC-142b), 1, 1, 2 -tetrafluoroethane (HFC-134A), 1, 1, 1, 3,3-pentafluorobutane (H FC-365mfc), 1,1, -difluoroethane (HFC-152a), 1, 1, 2,3,3, 3-heptafluoropropane (HFC-227ea) and 1, 1, 1, 3,3-pentafluoropropane (HFC-245fa). Hydrocarbon and hydrofluorocarbon blowing agents are preferred. Other blowing agents that may be used include, for example, formic acid, methyl formate, carbamates and adducts thereof, carbon dioxide, acetone, methylal or hydrofluoroolefin. A combination of blowing agents can be used. In a further embodiment, a hydrocarbon blowing agent is used. It is generally preferred to additionally include water in the formulation, in addition to the physical blowing agent.

The blowing agents are preferably used in a sufficient amount, so that the formulation cures to form a foam having a molded density from 16 to 160 kg / m3, preferably from 16 to 64 kg / m3 and especially from 20 to 48 kg / m3. To achieve these densities, the hydrocarbon or hydrofluorocarbon blowing agent is conveniently used in an amount ranging from about 10 to about 40, preferably from about 12 to about 35, parts by weight per 100 parts by weight of polyol (is). Water reacts with the isocyanate groups to produce carbon dioxide, which acts as an expansion gas. The water is suitably used in an amount within the range of 0.5 to 3.5, preferably 1.0 to 3.0 parts by weight per 100 parts by weight of polyol (s).

The reaction system for forming the polyisocyanurate will usually include at least one catalyst for the reaction of the polyols and / or water with the polyisocyanate. Suitable urethane-forming catalysts include those described by U.S. Patent No. 4,390,645 and WO 02/079340, both incorporated herein by reference. Representative catalysts include tertiary amine and phosphine compounds, chelates of various metals, acid metal salts of strong acids; strong bases, alcoholates and phenolates of various metals, salts of organic acids with a variety of metals, organometallic derivatives of tetravalent tin, As, Sb and trivalent and pentavalent Bi and metallic iron and cobalt carbonyls.

Tertiary amine catalysts are generally preferred. Among the tertiary amine catalysts are dimethylbenzylamine (such as ESMORAPID® DB from Rhine Chemie), 1,8-diaza (5,4,0) undecane-7 (such as POLYCAT® SA-1 from Air Products), pentamethyldiethylenetriamine (such as as POLYCAT® 5 from Air Products), dimetu 1 cid ohexylamine (such as POLYCAT® 8 from Air Products), triethylenediamine (such as DABCO® 33LV from Air Products), dimethylethylamine, n-ethylmorpholine, N-alkyldimethylamine compounds such as N- ethyl N, N-dimethylamine and N-cetyl?,? - dimethylamine, N-alkylmorpholine compounds such as N-ethylmorpholine and N-coco morpholine, and the like. Other tertiary amine catalysts that are useful include those sold by Air Products under the tradenames of DABCO® NE1060, DABCO® NE1070, DABCO® NE500, DABCO® TMR 30, POLYCAT® 1058, POLYCAT® 11, POLYCAT® 15, POLYCAT® 33, POLYCAT® 41 and DABCO® MD45, and those sold by Huntsman under the tradenames ZR 50 and ZR 70. In addition, certain amine-initiated polyols can be used in the present disclosure as catalyst materials, including those described in the document. WO 01/58976 A. Mixtures of two or more of the above can be used.

The catalyst is used in catalytically sufficient amounts. For the preferred tertiary amine catalysts, a suitable amount of the catalyst is from about 0.3 to about 2 parts, especially from about 0.3 to about 1.5 parts, of tertiary amine catalyst (s) per 100 parts by weight of the polyol (s).

For the formation of polyisocyanurates, it can be included a trimerization catalyst in the total reaction system for the production of a rigid foam. Said trimerization catalyst includes, for example, tris (dialkylaminoalkyl) -s-hexahydrotriazines such as 1, 3,5-tris (N, N-dimethylaminopropyl) -s-hexahydrotriazine, DABCO T R 30, DABCO K 2097; DABCO K15, potassium acetate, potassium octoate; POLYCAT 43, POLYCAT 46, DABCO TMR, DABCO® TMR-2, DABCO® TMR-3, DABCO® TMR-4, DABCO® TMR-5, CURITHANE 52, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide; alkali metal hydroxides such as sodium hydroxide; alkali metal alkoxides, such as sodium methoxide and sodium soproxide; and alkali metal salts of long chain fatty acids having from 10 to 20 carbon atoms and, in some embodiments, pendant hydroxyl groups. The amount of trimerization catalyst, when used, is generally from 0.5 to 5 percent by weight of the total polyol. In the further embodiments, the level of trimerization catalyst will be at least 1 percent by weight based on the polyol component up to 4 percent by weight.

The reaction system for forming the polyisocyanurate may also contain at least one surfactant, which helps to stabilize the cells of the composition as the gas evolves to form bubbles and expand the foam. Examples of suitable surfactants include salts of metal and alkali amine or fatty acids such as sodium oleate, sodium stearate, sodium ricinoleates, diethanolamine oleate, diethanolamine stearate, diethanolamine ricinoleate, and the like; the alkali metal and amine salts of sulfonic acids such as dodecylbenzenesulfonic acid and dinaphthylmethane disulfonic acid; ricinoleic acid; siloxane-oxalkylene polymers or copolymers and other organopolysiloxanes; oxyethylated alkylphenols (such as Tergitol NP9 and Triton X100, from The Dow Chemical Company); oxyethylated fatty alcohols such as Tergitol 15-S-9, from The Dow Chemical Company; paraffin oils; Beaver oil; ricinoleic acid esters; red turkey oil; peanut oil; paraffins; fatty alcohols; dimethylpolysiloxanes and origomeric acrylates and polyoxyalkylene and fluoroalkane side groups. These surfactants are generally used in the amount of 0.01 to 6 parts by weight, based on 100 parts by weight of the polyol.

Organosilicon surfactants are generally the preferred types. A wide variety of these organosilicon surfactants are commercially available, including those sold by Goldschmidt under the trade name TEGOS ® (such as the surfactants TEGOS ® B-8462, B8427, B8433 and B-8404), those sold by OSi Specialties under the name NIAX® (such as NIAX® L6900 and L6988 surfactants) as well as various products commercially available surfactants from Air Products and Chemicals, such as the surfactants DC-193, DC-198, DC-5000, DC-5043 and DC-5098.

In addition to the above ingredients, the reaction system forming polyisocyanurate can include various auxiliary components such as fillers, colorants, odor maskers, flame retardants, biocides, antioxidants, UV stabilizers, antistatic agents, viscosity modifiers and Similar.

Examples of suitable flame retardants include phosphorous compounds, halogen-containing compounds and melamine.

Examples of fillers and pigments include calcium carbonate, titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazines, recycled rigid polyurethane or polyisocyanurate foam and carbon black.

Examples of UV stabilizers include hydroxybenzotriazoles, zinc dibutyl triocarbamate, 1,6-di-tertiary butyl catechol, hydroxybenzophenones, amines and phosphites inhibited.

Except for filling materials, the above additives are generally used in small amounts. Each one can constitute from 0.01 percent to 3 percent of the total weight of the reaction system that forms the polyisocyanurate. The fillers can be used in amounts as high as 50% of the total weight of the polyisocyanurate formation reaction system.

The polyisocyanurate formation reaction system is prepared by bringing the various components together under conditions, such that the polyol and isocyanate reactions, the blowing agent generates a gas, and the composition expands and cures. All the components (or any sub-combination thereof) except the poly-isocyanate can be pre-mixed in a formulated polyol composition if desired, which is subsequently mixed with the poly-isocyanate when the foam is to be prepared. The components can be pre-heated if desired, but this is usually not necessary, and the components can be placed together at approximately room temperature (~ 22 ° C) to drive the reaction. Normally it is not necessary to apply heat to the composition to promote curing, although this can also be done, if desired.

The present invention is particularly useful in the production of composite elements, which include, for example. at least one lining layer of a rigid or flexible material and a central layer of a rigid foam. In another embodiment, the composite element includes at least two outer layers of a rigid or flexible material with the core foam layer rigid sandwich between them.

For outer layers or linings, it is in principle possible to use any of the flexible or rigid linings used in a conventional manner, such as aluminum (lacquered and / or anodized), steel (galvanized and / or lacquered), copper, stainless steel, and non-metals, such as non-woven organic fibers, plastic sheets (eg, polystyrene), plastic sheets (eg, PE sheet), wood sheets, glass fibers, impregnated paperboard, paper or laminate mixtures thereof. It is generally preferred to use metallic linings, particularly made of aluminum and / or steel. The thickness of the linings is generally from 200 pm to 5 mm. In the additional modalities, the thickness is greater than 300 μ? T? or greater than 400 μ ?? In the additional embodiments, the thickness is less than 3 mm or less than 2 mm. Galvalumne ™ metal fittings are an example of commercially available fittings.

Other exemplary methods for applying the polyisocyanurate foams described herein are described in US documents 7,540,932, US 2007/0246160, WO 2008/018787 and WO 2009/077490.

In certain embodiments, it may be advantageous to apply one or more layers that promote adhesion prior to the application of the polyisocyanurate formulation to improve the addition between the polyisocyanurate formulation and other portions of the polyisocyanurate formulation. compound element. The adhesion-promoting layer can be based on polyurethane or polyisocyanurate. The adhesion promoting layer can be obtained by reacting (a) polyisocyanates with (b) compounds having two hydrogen atoms reactive towards the isocyanate.

The foam layer will generally be from 2 cm to 25 cm thick. In other embodiments, the foam layer is from 2.5 to 21 cm and in a particular embodiment, from 6 to 16 cm. The double band conveyor belt will generally be heated to a temperature within the range of 35 ° C to 75 ° C. Preferably, the double conveyor belt will be at temperatures from 45 ° C to 60 ° C.

Applications for panels produced include use in walls, ceilings and interior separation construction.

EXAMPLES The objects and advantages of the embodiments described in the present description are further illustrated through the following examples. The materials and particular amounts thereof, as well as other conditions and details, cited in these examples, will not be used to limit the modalities described in the present description. Unless stated otherwise, all percentages, parts and proportions are by weight. The examples of the present invention are numbered, while the samples Comparatives, which are not examples of the present invention, are designated alphabetically.

A description of the raw materials used in the examples is as follows.

VORANOL ™ 360 is a polyether polyol of sucrose / glycerin having a functionality of about 4.5 and a hydroxyl number of about 460, available from The Dow Chemical Company.

Polyol TERATE®-2031 is a polyester polyol based on dimethyl terephthalate available from Invista.

Polyester A is a polyester polyol based on terephthalic acid, diethylene glycol, glycerin and polyethylene glycol 200 as described in the present disclosure.

TCPP, Tris (chlorosopropyl) phosphate, is a flame retardant additive of low viscosity and low acid available from Supresta.

DABCO® DC 193 is a silicone surfactant available from Air Products (DABCO is a trademark of Air Products).

Catalyst DABCO® K-15 is a catalyst solution of potassium octoate in diethylene glycol available from Air Products.

ARALDITE® Resin CY179 is a multifunctional alicyclic diepoxy carboxylate resin available from Huntsman Advanced Materials Inc.

POLYCAT® 8 is an amine catalyst of N, N-dimethylcid ohexyl, available from Air Products.

HFC-245fa, 1, 1, 1, 3,3-pentafluoropropane, is a blowing agent available under the trade name ENOV ATE® from Honeywell.

Polymeric MDI PAPI ™ 580N is a polymethylene polyphenylisocyanate containing MDI available from The Dow Chemical Company.

TYZOR® AA-105 catalyst (acetylacetonates) which is a chelate of titanium acetylacetonate commercially available from DuPont.

The properties of the polyester polyols and the formulations incorporating said polyesters to produce a polyisocyanurate foam are provided in Tables 1 and 2, respectively. The raw materials shown in Table 1 are charged to a reactor equipped with a nitrogen inlet tube, pneumatic agitator, thermometer and condenser. The heat is applied and the content of the reactor raised to a temperature of 230 to 235 ° C. At a temperature of 210 ° C, a titanium acetylacetonate catalyst (Tyzor AA-105 from Dorf Ketal) was charged at 50 ppm and nitrogen flow applied. The mixture is maintained at a temperature of 230 to 235 ° C for 5 hours. The polyester at this point has an acid number below 2.0 mgKOH / g and the properties described in Table 1.

Table 1: Properties of Polyester Polyol To commercial Polyol commonly used to make flame retardant polyisocyanurate foams, the exact composition is not known.

Table 2 Formulations The properties of the polyisocyanurate foams produced are given in Table 3.

Table 3 Results For the strength tests, a free-lift sample was mixed by hand and poured into a tall wooden mold 8 inches (30.3 cm) long by 8 inches (20.3 cm) wide by 9.5 inches (24.1 cm) high (room temperature). Sufficient material was mixed to produce a foam, so that the finished sample is raised enough to form a flat surface on the sides of at least 8 inches (20.3 cm) in height. The foam was allowed to cure in the mold until 1 minute before the desired test time, ie 29 minutes during a 30 minute test result.

The resistance test procedure was performed on an Instron 5566 extra-wide material test system. The load cell (UK 537 / 2,000 Ib) was mounted on a projection that is mounted on the vertical guides of the load frame. He The test specimen was placed on a test stage and subsequently compressed by an 8-inch (20.3 cm) diameter denting foot, which was fixed to the load cell.

To begin the resistance test, the foam sample was placed horizontally (compared to the emptying) and centered on the Instron test stage. 15 seconds before the desired time [29 minutes 45 seconds after the mold removal for a 30 minute test] the test was started. This started the Instron to lower the projection from the start 228.6 mm (9 inches (22.9 cm)) from the high position at a rate of 100 mm / min until the load cell makes contact with the foam sample. The projection continued to decrease until a force of 8.9 N (2.0 Ibf) was reached, at which time the thickness was recorded automatically. Then, the projection descends again; this time at an index of 305mm / min until a compression of 25.4 mm (compared to 2.0 Ib3) thickness was obtained) at which time, the maximum compression load (resistance) was recorded automatically. The strength values provide an indication of the ability of molded or cast products to withstand handling, mold ejection and machining before they are fully cured or hardened.

The foams produced using the formulation of the Example # 1 represented in Table 2, resulted in a polyisocyanurate foam having a similar reactive profile, but with a superior strength during the typical time frame in which, a double lining panel could be processed through a double band lamination system (for example, less than 8 minutes). This superior resistance of similar reactivity will result in a panel having an increased "hardness" at the end of the customer's line and a reduced potential for subsequent expansion, shrinkage and deformation and stacking and handling damage.

Although the foregoing is directed to the embodiments of the present invention, other additional embodiments of the present invention may be visualized without departing from the basic scope thereof, and the basic scope thereof.

Claims

1. A polyester, which is the reaction product of at least: (a) an aromatic component comprising 80 mole percent or more of terephthalic acid; (b) at least one polyether polyol having a nominal functionality of 2, a molecular weight of 150 to 1,000 and a polyoxyethylene content of at least 70% by weight of the polyether polyol; (c) at least one deferent glycol of (b) having a nominal functionality of 2 and a molecular weight of 60 to 250; Y (d) at least one polyol having a molecular weight of 60 to 250 and a nominal functionality of at least 3; wherein, a, b, c, and d are present in the reaction on a weight percent basis of 20 to 60 percent by weight of (a), 20 to 50 percent by weight of (b), 10 to 30 percent by weight of (c), and 5 to 20 percent by weight of (d).

2. The polyester as described in claim 1, further characterized in that the aromatic component comprises 85 mole percent or more of terephthalic acid.

3. The polyester as described in claims 1 to 2, further characterized in that component (c) is ethylene glycol, diphenyl glycol I, or oxyalkylene glycol of the formula: OH- (CH2-CH-0) N-H I R (Formula I) wherein R is hydrogen or a lower alkyl of 1 to 4 carbon atoms and n is selected to provide a molecular weight of 250 or less.

4. The polyester as described in claims 1 to 3, further characterized in that component (c) is diethylene glycol, and polyethylene glycol having a molecular weight of 200 or less.

5. The polyester as described in claims 1 to 4, further characterized in that component (d) is glycerin.

6. The polyester as described in claims 1 to 5, further characterized in that the polyester has a functionality between 2.3 and 2.7.

7. The polyester as described in claims 1 to 6, further characterized by having a viscosity of less than 15,000 cps (mPa * s) at a temperature of 25 ° C as measured by UNI EN ISO 3219.

8. A reaction system for the production of a rigid foam, comprising: (A) a polyol formulation comprising: (1) a polyester, which is the reaction product of: (a) an aromatic component comprising 80 mole percent or more of terephthalic acid; (b) at least one polyether polyol having a nominal functionality of 2, a molecular weight of 150 to 1,000 and a polyoxyethylene content of at least 70% by weight of the polyether polyol; (c) at least one deferent glycol of (b) having a nominal functionality of 2 and a molecular weight of 60 to 250; Y (d) at least one polyol having a molecular weight of 60 to 250 and a nominal functionality of at least 3; where, (a), (b), (c), and (d) are present in the reaction on a percentage basis by weight of 20 to 60 percent by weight of (a), 20 to 50 percent by weight of (b), 10 to 30 percent by weight of (c), and 5 to 20 percent by weight of (d); (B) one or more polyisocyanate components; (C) blowing agents; (O) catalyst; Y (E) optionally, additives and auxiliaries.

9. The reaction system as described in claim 8, further characterized in that the polyisocyanate is in an amount sufficient to provide an isocyanate index from 150 to 800.

10. The reaction system as described in claim 8 or 9, further characterized in that the one or more polyisocyanate components (B) is a polymethylene polyphenylisocyanate containing methylene diphenyl diisocyanate (MDI).

11. The reaction system as described in claims 8 to 10, further characterized in that the polyol formulation further comprises: (2) an additional polyether polyol other than (b), (c) and (d) having a functionality of 2 to 8 and a molecular weight of 100 to 2,000.

12. A composite element comprising: i) a lining layer; ii) a rigid foam comprising the reaction product of: (A) a polyol formulation comprising: (1) a polyester, which is the reaction product of: (a) an aromatic component comprising 80 mole percent or more of terephthalic acid; (b) at least one polyether polyol having a nominal functionality of 2, a molecular weight of 150 to 1,000 and a polyoxyethylene content of at least 70% by weight of the polyether polyol; (c) at least one deferent glycol of (b) having a nominal functionality of 2 and a molecular weight of 60 to 250; Y (d) at least one polyol having a molecular weight of 60 to 250 and a nominal functionality of at least 3; where, (a), (b), (c), and (d) are present in the reaction on a percentage basis by weight of 20 to 60 per percent by weight of (a), 20 to 50 percent by weight of (b), 10 to 30 percent by weight of (c), and 5 to 20 percent by weight of (d); (B) a polyisocyanate component; (C) blowing agents; (D) catalyst; Y (E) optionally, additives and auxiliaries.

13. The composite element as described in claim 12, further characterized in that the polyol formulation further comprises: (2) an additional polyether polyol other than (b), (c) and (d) having a functionality of 2 to 8 and a molecular weight of 100 to 2,000.

14. The composite element as described in claim 13, further characterized in that the polyol formulation comprises: from 20 to 90% by weight of the polyester; Y from 10 to 80% by weight of the additional polyether polyol.

15. The composite element as described in claims 12 to 14, further characterized by additionally comprising: (iii) an additional lining layer, wherein the rigid foam is formed between the lining layer and the additional lining layer.